This Demonstration solves the differential equation for a damped swing pendulum, . Interestingly, starting from a vertical position with zero initial velocity, Mathematica starts the motion on its own (for a small-enough damping constant) because of numerical roundoff errors, somewhat similar to effects which occur in chaotic dynamics.

Contributed by: Balázs Kiss (Budapest University of Technology and Economics)

Additional contributions by: János Tóth, Attila Nagy